1 files changed, 64 insertions, 44 deletions

diff --git a/arch/arm/include/asm/mmu_context.h b/arch/arm/include/asm/mmu_context.h
index de6cefb329d..9b32f76bb0d 100644
--- a/arch/arm/include/asm/mmu_context.h
+++ b/arch/arm/include/asm/mmu_context.h
@@ -18,61 +18,79 @@
 #include <asm/cacheflush.h>
 #include <asm/cachetype.h>
 #include <asm/proc-fns.h>
+#include <asm/smp_plat.h>
 #include <asm-generic/mm_hooks.h>
 
-void __check_kvm_seq(struct mm_struct *mm);
+void __check_vmalloc_seq(struct mm_struct *mm);
 
 #ifdef CONFIG_CPU_HAS_ASID
 
-/*
- * On ARMv6, we have the following structure in the Context ID:
- *
- * 31                         7          0
- * +-------------------------+-----------+
- * |      process ID         |   ASID    |
- * +-------------------------+-----------+
- * |              context ID             |
- * +-------------------------------------+
- *
- * The ASID is used to tag entries in the CPU caches and TLBs.
- * The context ID is used by debuggers and trace logic, and
- * should be unique within all running processes.
- */
-#define ASID_BITS		8
-#define ASID_MASK		((~0) << ASID_BITS)
-#define ASID_FIRST_VERSION	(1 << ASID_BITS)
-
-extern unsigned int cpu_last_asid;
+void check_and_switch_context(struct mm_struct *mm, struct task_struct *tsk);
+#define init_new_context(tsk,mm)	({ atomic64_set(&mm->context.id, 0); 0; })
 
-void __init_new_context(struct task_struct *tsk, struct mm_struct *mm);
-void __new_context(struct mm_struct *mm);
-
-static inline void check_context(struct mm_struct *mm)
+#ifdef CONFIG_ARM_ERRATA_798181
+void a15_erratum_get_cpumask(int this_cpu, struct mm_struct *mm,
+			     cpumask_t *mask);
+#else  /* !CONFIG_ARM_ERRATA_798181 */
+static inline void a15_erratum_get_cpumask(int this_cpu, struct mm_struct *mm,
+					   cpumask_t *mask)
 {
-	if (unlikely((mm->context.id ^ cpu_last_asid) >> ASID_BITS))
-		__new_context(mm);
-
-	if (unlikely(mm->context.kvm_seq != init_mm.context.kvm_seq))
-		__check_kvm_seq(mm);
 }
+#endif /* CONFIG_ARM_ERRATA_798181 */
 
-#define init_new_context(tsk,mm)	(__init_new_context(tsk,mm),0)
+#else	/* !CONFIG_CPU_HAS_ASID */
 
-#else
+#ifdef CONFIG_MMU
 
-static inline void check_context(struct mm_struct *mm)
+static inline void check_and_switch_context(struct mm_struct *mm,
+					    struct task_struct *tsk)
 {
-#ifdef CONFIG_MMU
-	if (unlikely(mm->context.kvm_seq != init_mm.context.kvm_seq))
-		__check_kvm_seq(mm);
-#endif
+	if (unlikely(mm->context.vmalloc_seq != init_mm.context.vmalloc_seq))
+		__check_vmalloc_seq(mm);
+
+	if (irqs_disabled())
+		/*
+		 * cpu_switch_mm() needs to flush the VIVT caches. To avoid
+		 * high interrupt latencies, defer the call and continue
+		 * running with the old mm. Since we only support UP systems
+		 * on non-ASID CPUs, the old mm will remain valid until the
+		 * finish_arch_post_lock_switch() call.
+		 */
+		mm->context.switch_pending = 1;
+	else
+		cpu_switch_mm(mm->pgd, mm);
+}
+
+#define finish_arch_post_lock_switch \
+	finish_arch_post_lock_switch
+static inline void finish_arch_post_lock_switch(void)
+{
+	struct mm_struct *mm = current->mm;
+
+	if (mm && mm->context.switch_pending) {
+		/*
+		 * Preemption must be disabled during cpu_switch_mm() as we
+		 * have some stateful cache flush implementations. Check
+		 * switch_pending again in case we were preempted and the
+		 * switch to this mm was already done.
+		 */
+		preempt_disable();
+		if (mm->context.switch_pending) {
+			mm->context.switch_pending = 0;
+			cpu_switch_mm(mm->pgd, mm);
+		}
+		preempt_enable_no_resched();
+	}
 }
 
+#endif	/* CONFIG_MMU */
+
 #define init_new_context(tsk,mm)	0
 
-#endif
+#endif	/* CONFIG_CPU_HAS_ASID */
 
 #define destroy_context(mm)		do { } while(0)
+#define activate_mm(prev,next)		switch_mm(prev, next, NULL)
 
 /*
  * This is called when "tsk" is about to enter lazy TLB mode.
@@ -101,15 +119,18 @@ switch_mm(struct mm_struct *prev, struct mm_struct *next,
 #ifdef CONFIG_MMU
 	unsigned int cpu = smp_processor_id();
 
-#ifdef CONFIG_SMP
-	/* check for possible thread migration */
-	if (!cpumask_empty(mm_cpumask(next)) &&
+	/*
+	 * __sync_icache_dcache doesn't broadcast the I-cache invalidation,
+	 * so check for possible thread migration and invalidate the I-cache
+	 * if we're new to this CPU.
+	 */
+	if (cache_ops_need_broadcast() &&
+	    !cpumask_empty(mm_cpumask(next)) &&
 	    !cpumask_test_cpu(cpu, mm_cpumask(next)))
 		__flush_icache_all();
-#endif
+
 	if (!cpumask_test_and_set_cpu(cpu, mm_cpumask(next)) || prev != next) {
-		check_context(next);
-		cpu_switch_mm(next->pgd, next);
+		check_and_switch_context(next, tsk);
 		if (cache_is_vivt())
 			cpumask_clear_cpu(cpu, mm_cpumask(prev));
 	}
@@ -117,6 +138,5 @@ switch_mm(struct mm_struct *prev, struct mm_struct *next,
 }
 
 #define deactivate_mm(tsk,mm)	do { } while (0)
-#define activate_mm(prev,next)	switch_mm(prev, next, NULL)
 
 #endif